The Levinthal Paradox

assumes that all of the

possible conformations

will be sampled with

equal probability until

the proper one (N = native)

is found. Thus, the funnel

surface looks like a hole

in a golf course. The paradox

states that if a protein samples

all 6M conformations it will take a time longer than the age of

the universe to find the native fold (N). Note that the statistical

entropy is S = RlnW = R ln(6M) = Mln(6)R in this example.

M = number of residues, 6 = number of conformations per residue